There isn't anything like that. PW5 is a totally locked down black-box. When you end up bricking it your only course of action would be finding someone that can remove the eMMC > write data to it > reattach the eMMC chip.
And you shouldn't be trying to test on a PW5 device all those ideas you've been inquiring about here on various topics. Buy a used PW3, setup Coward's Rescue Pack and then go nuts with testing and perfecting your software mod ideas.
And if you haven't already read this:
https://kb.taktpraha.cz/projects/kindlepw5